Fifth wheel hitches for towing a trailer behind a towing vehicle, such as a pickup truck, have long been known in the art. Examples of state of the art fifth wheel hitches include those presently manufactured by Reese Products, Inc. of Elkhart, Ind. under product numbers 30026, 30027 and 30028.
These state of the art fifth wheel hitches include a support frame for mounting the hitch to the towing vehicle, such as, for example, to the bed of a pickup truck. The support frame includes a pair of mounting rails that are bolted to the bed and/or frame of the truck, side brackets that are releasably mounted to the rails and a head support mounted to the side brackets. A head assembly is mounted to the head support by means of a trunnion arrangement allowing fore-and-aft pivotal movement. The head assembly includes a jaw assembly, operable by means of a control handle, that is specifically adapted to releasably engage and hold a king pin of a trailer desired to be towed by the towing vehicle.
While such state of the art fifth wheel hitches provide excellent overall performance and dependable operation, it has been found that improvements in design are still possible. More particularly, the state of the art fifth wheel hitches just described have a head assembly that allows for only fore-and-aft pivotal movement. No side-to-side pivotal movement is provided. Accordingly, under certain operating conditions including the traversing of a grade or when maneuvering at relatively low speed in a confined area and turning sharply, significant strain is placed upon the jaw assembly.
Recognizing this shortcoming, a new generation of fifth wheel hitch assemblies has recently been developed providing for both side-to-side and fore-and-aft pivotal movement of the head assembly. As a result, some of this strain placed on the jaw assembly is relieved. In this way the service life of the jaw assembly and, therefore, the fifth wheel hitch may be extended and the integrity of the coupling with the trailer enhanced. Further, significant improvements in low speed maneuverability are achieved. However, some users still prefer, at least under certain road and weather conditions, the more rigid towing platform provided by limiting pivotal movement exclusively to the fore-and-aft direction. A need is, therefore, identified for a fifth wheel hitch assembly allowing the operator to choose between a towing platform providing both fore-and-aft and side-to-side pivotal movement or fore-and aft pivotal movement alone.